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Highlighted USGS scienceMon, 20 Jul 2015 18:17:23 +0000en-UShourly1http://wordpress.org/?v=4.2.2Researchers Seek a Sneak Peek Into the Future of Forestshttp://www.usgs.gov/blogs/features/usgs_top_story/researchers-seek-a-sneak-peek-into-the-future-of-forests/
http://www.usgs.gov/blogs/features/usgs_top_story/researchers-seek-a-sneak-peek-into-the-future-of-forests/#commentsTue, 07 Jul 2015 16:59:07 +0000http://www.usgs.gov/blogs/features/?post_type=usgs_top_story&p=215973Read more]]>In May 2015, scores of scientists from dozens of research institutions descended on a patch of forest in central North Carolina, taking samples of everything from ants and mites to other microbes – samples they hope will offer a glimpse into the future of forest ecosystems.

This flurry of data collection represents the largest and most robust warming experiment conducted in a forest ecosystem. The project is supported by the U.S. Geological Survey and the Department of the Interior’s Southeast Climate Science Center, based at North Carolina State University (NCSU).

The heart of the experiment is a collection of so-called warming chambers – a dozen octagonal rooms, 5 meters in diameter, scattered throughout Duke Forest, across Durham, Orange, and Alamance counties in NC. The rooms had neither roofs nor floors, and were ringed with clear, plastic ductwork that pumped warm air into each chamber. Three of the chambers were kept at the same temperature as the surrounding forest. The other nine chambers were warmer, with internal temperatures that ranged from 1.5° Celsius (~35° Fahrenheit) to 5.5° Celsius (~ 42° Fahrenheit) higher than the ambient temperature. The North Carolina warming chambers had been running since January 2010 until they were taken down in May 2015 and have a sister site in Massachusetts’s Harvard Forest with a similar collection of warming chambers.

Insects, Trees, and Soils Respond

“We know that ants are an important part of forest ecosystems, and we found that warming has a significant impact on ant diversity in forests,” says Clint Penick, a postdoctoral researcher at NCSU who works at the site. “Some ant species populations decline dramatically, while other ant populations grow. One ant that fared poorly at higher temperatures is the winnow ant (Aphaenogaster rudis) – a common ant in eastern U.S. forests that plays a crucial role in seed dispersal. A species of acrobat ant, on the other hand, is becoming much more common.” Others still, such as the invasive needle ant, seem to thrive regardless of the temperature.

For both ants and trees, the researchers have been able to identify key features of the species that succeed with warming and those that fail; in general, what they see in the chambers matches what is going on in urban heat islands across the country – as well as ecological changes stemming from temperature changes in the Southeast over the past hundred years. The researchers also learned that the impact of climate change appears to be very different in regions such as North Carolina versus cooler regions such as Massachusetts. This indicates that, at least for the species the team has studied so far, increases in temperature are likely to have a bigger ecological impact in areas that were warmer to begin with.

So Much More to Learn

Now, thanks to support from Interior’s Southeast Climate Science Center, the team has reached out to scholars from around the world to help them study the full suite of organisms present in each chamber. And dozens of researchers have answered the call.

“As we got closer to the end-date for the warming chamber site, we invited a slew of scientists interested in diversity questions to work on collecting samples from the chambers,” says Lauren Nichols, an NCSU researcher who has worked on the project from the beginning. “Collectively, it should give us a good overview of how shifts in temperature may change a forest – from the microbial level up.”

Already, researchers from nine universities are also looking at different aspects of soil core samples to see how microbial communities have changed over time at different temperatures.

“And because samples of plants, soils and insects are being saved and curated like museum specimens, the samples can and will be studied by people not yet involved in the project,” says Rob Dunn, a professor of biology at NCSU and one of the primary investigators on the warming chambers project.

This will allow people from all walks of life, including formal researchers, to engage in studying the forests of the future for many years to come. “When it is all said and done, these chambers may be not only the biggest warming experiment in a forest yet, but also the most intensive and collaborative study of any patch of forest,” Dunn says. Dunn’s research partners are Nate Sanders of the University of Copenhagen, Aaron Ellison of Harvard Forest and Nick Gotelli of the University of Vermont.

“We’ll be seeing discoveries come out of this work for years to come,” ant researcher Penick says. And, says Dunn, “We hope to still see new collaborators signing up to help us to study the experiment, because even as the chambers come down we are saving everything we can, from dirt to leaves that in the future others can study what we fail to pay attention to now. The more people that help us to see, the more light we will shine on the warmer future, a future that is coming whether or not we spend the time trying to understand.”

Mistletoe can take many forms other than the American mistletoe with berries seen around the holidays.

Perhaps some of you have already experienced a sweet holiday smooch or two under the Christmas mistletoe, enjoying this fairly old kissing ritual for people. But mistletoe is important in other vital ways: it provides essential food, cover, and nesting sites for an amazing number of critters in the United States and elsewhere. In fact, some animals couldn’t even survive without mistletoe, including some birds, butterflies, and insects.

But first, a little bit about the plant. The white-berried Christmas mistletoe we hang so hopefully in places where our sweethearts will find us lingering is just one of more than 1,300 species of mistletoe worldwide. Globally, more than 20 mistletoe species are endangered. Two kinds of mistletoes are native to the United States: the American mistletoe (the one commonly associated with our kissing customs) and the dwarf mistletoe. American mistletoe is found from New Jersey to Florida and west through Texas. The dwarf mistletoe, much smaller than its kissing cousin, is found from central Canada and southeastern Alaska to Honduras and Hispaniola, but most species are found in western United States and Mexico.

Mistletoe is no newcomer to this country: excavations of packrat middens reveal that dwarf mistletoes have been part of our forests for more than 20,000 years. Some fossil pollen grains even indicate that the plant has been here for millions of years. Mistletoes, said USGS researcher Todd Esque, should be viewed as a natural component of healthy forest ecosystems, of which they have been a part for thousands, if not millions of years.

Thief of the Tree

The thing that all mistletoes have in common is this: all grow as parasites on the branches of trees and shrubs. In fact, the American mistletoe’s scientific name, Phoradendron, means “thief of the tree” in Greek. The plant is aptly named: it begins its life as a handily sticky seed that often hitchhikes to a new host tree on a bird beak or feather or on mammal fur. In addition to hitchhiking, the dwarf mistletoe also has another dandy way of traveling to a new host tree: the seeds of this mistletoe will, like tiny holiday poppers, explode from ripe berries, shooting a distance as far as 50 feet. One researcher said that if you put ripe berries in a paper bag and shake it, it sounds just like popping popcorn.

For the most part, the mistletoe is pretty darn cavalier about what host tree it finds — dwarf mistletoes like most kinds of conifers; American mistletoes are found on an incredible variety of trees. Once on a host tree, the mistletoe sends out roots that penetrate the tree and eventually starts pirating some of the host tree’s nutrients and minerals. In actuality, mistletoes are not true parasites; instead they are what scientists call “hemi-parasites” because most of them have the green leaves necessary for photosynthesis. Still, it seems like a pretty lazy life for most mistletoes: a little photosynthesis here and there and a lot of food and water stolen from their unsuspecting benefactor trees. Eventually, mistletoes grow into thick masses of branching, misshapen stems, giving rise to a popular name of witches’ brooms, or the apt Navajo name of “basket on high.”

Birds and the Mistletoe Trees

The plant’s common name — mistletoe — is derived from early observations that mistletoe would often appear in places where birds had left their droppings. “Mistel” in the Anglo-Saxon word for “dung,” and “tan” is the word for “Twig.” Thus, mistletoe means “dung-on-a-twig.” Yet even though bird droppings cannot spontaneously generate mistletoe plants, birds are an important part of mistletoe life history — and vice versa. A surprising variety of birds use or rely on mistletoe. In studies by former USGS scientist Rob Bennetts and other studies, a high abundance of dwarf mistletoe in a forest means that more kinds and numbers of birds inhabit that forest. Also, since the lifespan of mistletoe-laden trees is considerably shorter than trees where the plant is absent, a higher number of tree snags occupy mistletoe-laden woods. Not surprisingly, this means that more — one study documented at least three times as many — cavity-nesting birds live in forests with abundant mistletoes. The phainopeplas, a silky flycatcher, are beautiful birds that live in the desert areas of the Southwest and West and are especially dependent on mistletoe.

Diane Larson, a USGS researcher, studied mistletoes and birds in Arizona. “I found that phainopeplas, which rely on mistletoe almost exclusively for food during the winter, were also the species most likely to disperse the mistletoe seeds to sites suitable for germination and establishment. Both the bird and the plant benefited from this relationship,” says Larson. USGS researcher Esque said his goal is to understand the distribution of the host trees in relation to mistletoe patterns and bird behavior. “We know the relationship is mutually beneficial for both species,” said Esque. Some research indicates that if mistletoe-berry production is poor, these birds may not breed the following spring.

But the phainopepla is just one of many birds that eat mistletoe berries; others include grouse, mourning doves, bluebirds, evening grosbeaks, robins, and pigeons. Naturalist and writer John Muir noted American robins eating mistletoe in the mountains of California in the late 1890’s. Wrote Muir: “I found most of the robins cowering on the lee side of the larger branches of the trees, where the snow could not fall on them, while two or three of the more venturesome were making desperate efforts to get at the mistletoe berries by clinging to the underside of the snow-covered masses, back downward, something like woodpeckers.”

Birds also find mistletoe a great place for nesting, especially the dense witches’ brooms. In fact, northern and Mexican spotted owls and other raptors show a marked preference for witches’ brooms as nesting sites. In one study, 43 percent of spotted owl nests were associated with witches’ brooms. Similarly, a USGS researcher found that 64 percent of all Cooper’s hawk nests in northeastern Oregon were in mistletoe. Other raptors that use witches’ brooms as nesting sites include great gray owls, long-eared owls, goshawks, and sharp-shinned hawks. Likewise, some migratory birds also nest in witches’ broom — gray jay, northern beardless-tyrannulet, red crossbills, house wrens, mourning doves, pygmy nuthatches, chickadees, Western tanagers, chipping sparrows, hermit thrushes, Cassin’s finches, and pine siskins. “A well-disguised nest provides protection against predators such as the great horned owls,” Bennetts said.

Bees, Butterflies, and Others

According to butterfly expert and Colorado State University professor Paul Opler, three kinds of butterflies in the United States are entirely dependent on mistletoes for their survival: the great purple hairstreak, the thicket hairstreak, and the Johnson’s hairstreak. The great purple hairstreak, says Opler, is the only butterfly in the United States that feeds on American mistletoe, the Christmas mistletoe. This beautiful butterfly lays its eggs on the mistletoe, where the resulting caterpillars thrive on a mistletoe diet. The caterpillars of the other two butterflies feed on dwarf mistletoes. The Johnson’s hairstreak, restricted to the Pacific states, is usually found in association with old-growth conifer forests, the same places spotted owls prefer. The caterpillars of these butterflies closely mimic the appearance of the mistletoe with their mottled green and olive shades. Like people, the butterflies of these species use mistletoe for courtship rituals. After courting and mating in the mistletoe high in the canopy, the adults leave their eggs behind in the mistletoe. The adults of all three species drink nectar from the mistletoe flowers.

Mistletoe is also important nectar and pollen plant for honeybees and other native bees, says Erik Erikson, a bee researcher at the USDA Bee Research Lab. Mistletoe flowers, says Erikson, often provides the first pollen available in the spring for the hungry bees. “We look upon it as an important starter food source for the bees,” said Erikson. Wind and insects are important mistletoe pollinators. Although hundreds of kinds of insects carry mistletoe pollen, only a few dozen are important pollinators; these include a variety of flies, ants, and beetles. Yet other insects eat the shoots, fruits, and seeds of the mistletoe, including some that feed exclusively on the plant. Exclusive mistletoe-eaters include a twig beetle, several thrip species, and a plant bug whose coloration mimics dwarf mistletoe fruits. In addition, at least four mite species seem to be exclusively associated with dwarf mistletoe.

Mistletoe in abundance clinging to its host tree.

And Then There’s the Mammals

Don’t try it at home, kids and grown-ups — mistletoe is toxic to people, but the berries and leaves of mistletoe provide high-protein fodder for many mammals, especially in autumn and winter when other foods are scarce. Researchers have documented that animals such as elk, cattle and deer eat mistletoe during winter when fresh foliage is rare. In Texas, some ranchers even consider mistletoe on mesquite as an insurance forage crop, which the ranchers remove from the trees for cattle food when other forage is scarce. Other mammals that eat mistletoe include squirrels, chipmunks, and even porcupines, some of which are deliriously fond of the plant. A variety of squirrels, including red squirrels, Abert squirrels and flying squirrels often use witches brooms for cover and nesting sites.

A Blessing or a Bane?

Not everyone likes mistletoe. Many commercial foresters consider the dwarf mistletoe as a disease that reduces the growth rates of commercially important conifer species, such as the ponderosa pine. Ecologists, though, point out that mistletoes are not a disease; instead, they are a native group of plants that have been around thousands, or even millions, of years.

Blessing or bane, it is certain that mistletoe is not spreading like wildfire — in fact, mistletoe spreads only about 2 feet per year. One study indicated that a 1.5-acre patch of mistletoe took about 60 to 70 years to form. Likewise, the death of an individual tree from dwarf mistletoe may take several decades, and widespread infestation of a forest stand may take centuries. Bennetts believes that the conflict with forest management and the perspective of mistletoes being a forest disease really only comes into play when the management objectives are to maximize timber harvest. Otherwise, he says, mistletoes have many positive attributes, including tremendous benefits for native wildlife. Thus, he says, when not in conflict with commercial timber management objectives, mistletoes should be viewed as a natural component of healthy forest ecosystems.

Says Bennetts: “I had the privilege of working with a biologist who had spent more than 50 years working on mistletoes. He began his work with the intent of finding a way to control this ‘forest pest,’ but in his later years, he even introduced dwarf mistletoe to some of the trees in his yard because he had grown to love this plant for what it is . . . a fascinating and natural part of forest ecosystem.”

Mistletoe FAQ’s

Q: What is the type of mistletoe most people think of during the holidays?

A:Phoradendron serotinum, also known as American mistletoe, is commercially harvested and sold around the world. This species typically grows on oak trees across North America, and is native to Mexico.

Q: How does mistletoe grow and spread?

A: Mistletoe spreads by seeds — the seeds in some mistletoe explode from a fruit and disperse themselves. Many North American types of mistletoe are distributed by birds either in their feces or due to the stickiness of the berries and seeds. They also may be cleaned from bird beaks onto the branches of trees where they grow. Once mistletoe germinate and become established, they have material similar to a root for a ground-dwelling plant. This material moves under the bark and that is how the mistletoe gains energy as well as nutrients from its host tree.

Q: Is mistletoe fruit more nutritious than comparable berries on other plants?

A: Yes, all 10 essential amino acids have been found in mistletoe fruit, as well as high carbohydrate fractions. Some mistletoe species (such as the Loranthus europaeus) are very high in fat content, while others are full of protein. In addition, in many arid areas (such as the Southwest U.S.), mistletoe fruit is a reliable source of water.

Q: What are the medical applications for mistletoe?

A: Mistletoe has been widely used in Europe and is regarded as the most widely used natural therapy for cancer. In addition, it has many uses in traditional Chinese medicine as well as in traditional indigenous groups in Australia and Latin America. Some of these uses involve compounds taken from their host tree (and concentrated), but most are related to lectins and other secondary compounds manufactured by the mistletoes themselves. Navajo medicinal uses include using Juniper mistletoe to create a soothing lotion for bug bites, to cure warts, and to ease stomach pain.

Q: Do trees infected with mistletoe die earlier than those uninfected?

A: This depends on a number of factors, including type of mistletoe and amount growing on trees. A parasite’s function is to not kill their host, however some parasites can have detrimental effects, and in high densities mistletoe can affect growth rates of their host trees. Direct effects on tree mortality are cited in very few documented studies and occur in very high mistletoe densities when the normal factors that keep mistletoe in line are not functioning properly. Dwarf mistletoe is an exception — their way of infecting trees is different, so they are more likely to have detrimental effects on their hosts. Even then, mortality is characteristically due to indirect effects such as bark beetles or fungal attacks. Contrary to negative effects of mistletoe on trees, many foresters consider mistletoe to be a powerful positive force in forests, weeding out those trees poorly suited for the area and ensuring long-term forest and tree health.

Q: What is the best way to permanently remove mistletoe from a tree?

A: Pruning out all branches with the mistletoe material (see question on how mistletoe grows and spreads) as soon as the plant appears should control the mistletoe and prevent its spread. First cut close the mistletoe, then look at the branch structure and prune approximately one foot below where the mistletoe physically appears in order to rid the host tree of the mistletoe plant.

Q: How do the dynamics of U.S. dwarf mistletoe (Arceuthobium) dispersal differ from the Phoradendron plants?

A: As well as using hydrostatic expulsion to shoot seeds at speeds up to 60 miles per hour and distances of 50 feet, many Arceuthobium (dwarf mistletoe) species also form ‘systematic’ infections in their host. Initial establishment involves the growth of an endophytic system — a network of vessels growing throughout the host tissue. Then, when the plant becomes reproductively mature, shoots may pop out anywhere on the tree, not just near the point of initial infection.

Q: Is there a phylogenetic “mistletoe” group, or are mistletoes a collection of unrelated species?

A: Mistletoes have evolved at least five times, all from root parasitic ancestors within the same Santalales plant order. They are all related and come from a single ancient ancestor, but the aerial parasitic habit has evolved multiple times. Mistletoes are grouped based on this convergent way of life (similar to mangroves or succulents), and are not a monophyletic group.

]]>http://www.usgs.gov/blogs/features/usgs_top_story/not-just-for-kissing-mistletoe-and-birds-bees-and-other-beasts/feed/0American mistletoeMistletoe can take many forms other than the American mistletoe with berries seen around the holidays.mistletoe-treeCrownMistletoe in abundance clinging to its host tree.Experiments Underestimate Climate Change Impacts to Plantshttp://www.usgs.gov/blogs/features/usgs_science_pick/experiments-underestimate-climate-change-impacts-to-plants/
http://www.usgs.gov/blogs/features/usgs_science_pick/experiments-underestimate-climate-change-impacts-to-plants/#commentsWed, 02 May 2012 17:30:56 +0000http://www.usgs.gov/blogs/features/?post_type=usgs_science_pick&p=174022

As the climate has warmed, many plants are starting to grow leaves and bloom flowers earlier. A new study published in the journal, Nature, suggests that most field experiments may underestimate the degree to which the timing of leafing and flowering changes with global warming.

Understanding how plants are responding to climate change will help develop more accurate indicators of spring, forecast the onset of allergy season or the chances of western wildfires, manage wildlife and invasive plants, and help inform habitat restoration plans.

In this new study, scientists evaluated the sensitivity of plants to changes in temperature using two sources: experimental plots versus historical observations from natural sites.

The experiments analyzed in this study were conducted by artificially inducing warming in small study plots, and then measuring plant responses. The historical observations entailed long-term monitoring of multiple species at natural ecological research sites without any manipulation. The date of leafing and flowering was synthesized for dozens of warming experiments and monitoring sites across the Northern Hemisphere.

Scientists conclude that compared to warming experiments, historical monitoring shows temperature sensitivity to be four times greater for leafing and over eight times faster for flowering.

On average, the warming experiments predicted that every degree rise in Celsius would advance plants’ flowering and leafing from half a day to 1.6 days, while historical observations indicate a temperature sensitivity of about 5 to 6 days per degree Celsius. The finding was strikingly consistent across species and datasets. Conclusions from this study are based on analysis of more than 1600 plant species on four continents.

The study of how climatic variations and trends impact seasonal events in plants and animals is termed “phenology.” This includes when cherry trees or lilacs blossom, when robins build their nests, when salmon swim upstream to spawn, or when leaves turn colors in the fall.

The study was conducted by an interdisciplinary team led by Elizabeth Wolkovich, with the University of British Columbia, and Ben Cook, with NASA-Goddard. The study was funded by the National Science Foundation, the State of California and the University of California, Santa Barbara. The U.S. Geological Survey (USGS) and the USA-National Phenology Network (USA-NPN) also provided support and assisted with assembling and analyzing historical phenological observations and climate data.

Future Tracks: Experiments and Observations

Observing changes in the seasonality of plants in Concord, Massachussets. Credit: A. Miller-Rushing

The authors of the Nature paper recognize the value of both experiments and monitoring. They call for standardization of measurements and protocols as well as improvements in experimental design, and continuation and expansion of long-term monitoring efforts like the USA-NPN.

The USA-NPN brings together citizen scientists, government agencies, non-profit groups, educators and students of all ages to monitor the impacts of climate change on plants and animals in the United States. The USA-NPN was established by the USGS in collaboration with the National Science Foundation.

“This study underscores the reasons for recent establishment of a USA-NPN to help track, understand, and hopefully forecast different species responses to climate variability and change across the U.S.,” said USGS scientist Julio Betancourt, who is a co-author of this new report.

You Can Help! Track the Pulse of our Planet

We need your help to track the pulse of our planet. Through the USA-NPN’s Nature’s Notebook, citizens across the nation are providing data on plants and animals.

People like you — gardeners, farmers, birders, hikers, anglers, joggers, or all-around nature enthusiasts — are already recording the recurring events they see in the lives of the plants and animals around them. This includes when cherry trees or lilacs blossom, when robins build their nests, when salmon swim upstream to spawn, or when leaves turn colors in the fall.

Become involved and sign up through the USA-NPN website, or contact the USA-NPN Executive Director Jake Weltzin at jweltzin@usgs.gov.

In parts of eastern Africa, drought is of increasing concern, as poor families suffer from food shortages and the inability to grow crops and sustain livestock. Stunted growth in children due to malnutrition has also been linked to climate trends in Africa.

Drought conditions are expected to continue as global temperatures continue to rise and rainfall declines across parts of eastern Africa.

This poses increased risk to millions of people in Africa who currently face potential food shortages.

What’s being done to help?

The USGS is involved in a variety of research efforts to help understand current and future conditions in Africa, helping to inform plans to provide aid.

The Famine Early Warning Systems Network, or FEWS NET, is one endeavor that has already made great strides in helping to address this issue. FEWS NET helps target more than $1.5 billion of assistance to more than 40 countries each year.

FEWS NET examines the populations of the developing world with the most food insecurity, identifying critical situations in which food aid will be needed. These are populations whose livelihoods are typically tied to subsistence rain-fed agriculture and pastoralism.

FEWS NET is sponsored by the U.S. Agency for International Development (USAID) Office of Food for Peace and the USGS is actively involved.

FEWS NET at the United Nations Climate Convention

A USGS presentation on FEWS NET will be a featured side event on November 30, 2011, at the United Nations 17th annual Conference of the Parties (COP-17) in Durban, South Africa. The convention’s purpose is to develop international agreements and a declaration of policies and practices for combating climate change and its impacts around the world.

A herder moves cattle through a barren landscape in eastern Africa.

Climate forecasts and remote sensing help spot future trouble

FEWS NET has developed its own climate services to provide decision makers with early identification of agricultural drought that might trigger food insecurity. Scientists use climate forecasts to develop forward-looking food security assessments that are based on expected agricultural outcomes for the season ahead.

Since networks of ground observation stations are often sparse or reported late in FEWS NET countries, satellite remote sensing of vegetation and rainfall fills in the gaps. Remote sensing from space allows for rapid, accurate assessments of a broad range of environmental and agricultural conditions. USGS scientists provide the technologies and expertise to support remote sensing for FEWS NET activities.

Early warning of famine in Somalia helps pre-position food supplies

On July 20, 2011, the United Nations declared parts of Somalia as a region of famine. The decision was supported by FEWS NET and USGS observational evidence of conditions in the area.

The declaration was the culmination of early warning communications encouraging — months before the crisis — that government and other agencies pre-position food and supplies in the region.

“None of the many uses of Earth-observing satellites is more vital — or has as much potential for prompting timely humanitarian intervention — as famine early warning,” said USGS Director Marcia McNutt. “Remote sensing from space allows USGS scientists to provide rapid, accurate assessments of a broad range of environmental and agricultural conditions.”

The eastern Horn of Africa, the continental region that encompasses Somalia, has experienced two consecutive seasons of very poor rainfall resulting in the worst drought in 60 years. Crops have failed, livestock deaths are widespread, and food prices are very high. While the rains this winter have been good, food prices remain high, and the food security situation remains insecure.

Stunted growth linked to malnutrition and climate change

Other USGS research is helping to identify the impacts of a changing climate on Africa’s people. Scientists recently discovered that malnutrition and dry hot living conditions are linked to stunted growth in Mali, West Africa.

USGS research found that Mali was becoming substantially warmer and a little bit drier. Scientists also knew that farmers and those who make a living raising sheep, cattle, goats, or camels were poor, and that stunted growth was occurring throughout Mali.

Scientists wondered if there could be a link between human health and increasingly warm and dry conditions.

To investigate, the USGS worked with the University of California, Santa Barbara, to study climate observations and demographic and health data. The Demographic and Health Survey program routinely compiles data from surveys in 90 countries to study trends in health and population. Scientists analyzed statistics on specific villages in Mali and found that there was a link between a warmer climate and increased stunting.

Population growth combined with the impacts of warming will further increase these health impacts.

Stunting was also linked to other factors, such as mother’s education and the water supply system. Women’s education, improved water supplies, and agricultural development could help to address malnutrition and stunting in Mali.

An article on this research was published in in the journal, Applied Geography, by San Diego State University, the University of California, Santa Barbara, and the USGS.

A Food Security Assessment in Somalia found severe impacts on livestock due to drought conditions.

Other studies underway

Other new research includes the discovery that the warming of the Indian and western Pacific oceans (which is linked to global warming) affects rainfall over large areas of the Horn of Africa. As the globe has warmed over the last century, the Indian Ocean and western Pacific have warmed especially fast.

The resulting warmer air and increased humidity over the Indian and western Pacific oceans produce more frequent rainfall in that region. The air loses its moisture during rainfall, and then flows westward and descends over Africa, leading to decreased rain in parts of eastern Africa. Trends toward increased frequency of drought that we are seeing now are likely to continue into the future as warming continues.

A few recent articles on this research were published in the journal, Climate Dynamics, by scientists with the USGS, the University of California, Santa Barbara, and Los Alamos National Laboratory. The most recent article concludes that global warming will lead to a decrease in rainfall during the summer monsoon season, from June to September, across southern Sudan, southern Ethiopia, and northern Uganda. Another article concluded that eastern Africa, particularly Kenya and southern Ethiopia, will also have a significant decrease in rainfall during the long-rains season from March to June.

USGS scientists are working hard to translate these technical studies into reports for decision makers. To date, they have completed summary fact sheets focused on Sudan and Kenya.

Scientists also found that some regions, like northern Ethiopia, are not getting drier due to current warming temperatures. Rainfall varies dramatically across all of eastern Africa, with high mountainous areas typically receiving many times the rainfall received in low-lying areas. Therefore, agricultural growth in these climatically safe regions could help offset rainfall declines in other locations.

Start with science

Scientists are looking at clues and changes in nature to understand the impacts of global warming. In Africa, impacts are seen across the landscape — on farms and even in humans.

By starting with science, well-informed decisions can be made to help Africa as it faces drought, famine, and health concerns.

FEWS NET partners include the USAID, Chemonics International, the USGS, NASA, NOAA, and the USDA. The Geography Department at the University of California, Santa Barbara, is a partner to the USGS in this effort.

Want more information?

Listen to a podcast interview with USGS scientists as they discuss ongoing efforts to understand conditions in Africa.

]]>http://www.usgs.gov/blogs/features/usgs_top_story/science-helping-to-save-lives-in-africa/feed/0Cropped Field in AfricaHerder Moving Cattle in AfricaDrought Impacts to Livestock in Somalia